Dear Marco
Thank you very much for your answer.
To your comment in a) (see below): with the parameters obtained during
NewSegment I mean that I computed deformation fields (forward). I used this
fields to warp the data of my subjects to the TOM-template. Could I used
these deformation fields to transform the ROIs from MNI to the TOM-space?
I also thought about using the VBM statistical analysis to do the ROIs, but
here I compared two groups of children (A and B). In both groups I get
different activations. For example in one group the frontal cortex shows
some activation and in the other group not. I would derive the ROIs from A
or/and from B, but since I would like to correlate the data of the VMB with
the data of the fMRI I'm not sure if this procedure is correct. I mean
because I would not derive the ROIs from an independent analysis (for
example from another study).
Comment in b): concerning the quality of the data is there any argument to
prefer TOM instead of the MNI-procedure?
I thank you in advance for your help.
All the best,
Natalia
-----Ursprüngliche Nachricht-----
Von: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] Im
Auftrag von Marko Wilke
Gesendet: Mittwoch, 24. Juli 2013 08:39
An: [log in to unmask]
Betreff: Re: [SPM] question about
Hello N.,
> I’m working on a study with children (10-16 years) and I would like to
> performed a ROI analysis on my data. Since there is no predefine ROIs
> for children (as for example the Anatomy toolbox ROIs for adults) and
> I don’t have the capacity to performed anatomical ROIs by my own, I
> would like to use ROIs based on adult brains (in MNI) for my analyses.
> I used the TOM-toolbox to developed TPMs and enter these in
> “NewSegment” to perform the segmentation. Is it possible to use the
> parameters I obtained from this step to convert the ROIs in MNI space
> into the space of the TPMs, I’ve build with the TOM-toolbox?
I do not understand exactly what you mean by that but for transforming an
already normalized region of interest into the space of the TOM tpm, the
individual spatial normalization parameters will not help you. What you
could do is something along the lines of the procedure we did some years ago
(Wilke et al., 2003, PMID 14527581), i.e., take an "adult" ROI and use a
non-linear transformation to bring it into your pediatric TPM space. I would
suggest to use ROIs that are not very small, and potentially smooth them
slightly. Alternatively, you could derive a region of interest from a
statistical analysis on your own data (i.e., a cluster from a VBM or fMRI
study), which would also alleviate the problem.
> I also saw that based on the NIHPD some templates were developed for
> children. If I understand it correct these templates are in MNI space.
> Would it better to use these templates or the procedure I described above?
I would naturally argue to use TOM :) but either way, the procedures
described above would work in both cases.
> For your help I thank you in advance.
You're welcome :)
Cheers,
Marko
--
____________________________________________________
PD Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Universitäts-Kinderklinik
Abt. III (Neuropädiatrie)
Marko Wilke, MD, PhD
Pediatrician
Head, Experimental Pediatric Neuroimaging
University Children's Hospital
Dept. III (Pediatric Neurology)
Hoppe-Seyler-Str. 1
D - 72076 Tübingen, Germany
Tel. +49 7071 29-83416
Fax +49 7071 29-5473
[log in to unmask]
http://www.medizin.uni-tuebingen.de/kinder/epn/
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